Opportunistic Scheduling and Spectrum Reuse in Relay-Based Cellular OFDMA Networks

We investigate the spectral efficiency performance of channel-aware (i.e., opportunistic) multiuser scheduling algorithms over relay-assisted broadband cellular networks; with special focus on orthogonal frequency-division multiple-access (OFDMA) resource allocation. Capacity analysis and system-level simulation results for various spectrum reuse policies are presented including (i) fully orthogonal resource sharing across the base station (BS) and relay stations (RSs) in each cell, and (ii) simultaneous transmissions (i.e., at the same time and frequency) by the BS and multiple RSs in each cell, using realistic broadband channel models. Our study provides insights on the potential performance enhancements from multihop routing and spectrum reuse policies in the presence of multiuser diversity gains from opportunistic scheduling and helps to identify the key design tradeoffs associated with interference management in relay-assisted multiuser communication.